Fetal Development

Week Three: Cells Join, Divide - New life begins

3 weeks - Once a month around the 14th day, one of the eggs travels down into the fallopian tube. This is ovulation. If in the next 36 to 48 hours just one of the 350 million sperm in the average ejaculate can get all the way from the vagina through the uterus and into the fallopian tube to penetrate the egg, the egg will become fertilized. Sperm can live for up to 5 days in this environment, therefore making pregnancy possible for up to 5 days after intercourse.

The fertilized egg immediately begins dividing and floats down into the uterus. Immediately upon fertilization your little one is set as a boy or a girl. Ladies, this is one that you can not take credit for since it is up to the sperm to determine the sex of your baby. Sperm carries either a "X" (girl) chromosome or a "Y" (boy) chromosome.

The cells contains all of the genetic information (DNA) necessary to become a child. The baby begins to form from this single fertilized egg, the cell starts to divide itself into 2 cells, then 4, 8 and so on rapidly. Forty-six chromosomes combined, which pre-determine all of a person's physical characteristics. The fertilized egg is still rapidly dividing as it floats down from the fallopian tube and towards the uterus. The embryo first moves into the uterus at about 80 hours after ovulation. The implantation process begins about 3 days later. When it reaches the uterus, the fertilized egg burrows into the lining of the uterus.